The present invention relates to a numerically controlled tool, and more particularly to improved structures of clamp head of numerically controlled cutting tool.
A numerically controlled cutting tool is a precision machinery, which is a product of modern high technology; nevertheless it is by no means perfect. The clamp head of a numerically controlled cutting tool and its cooling system currently available are not as good as they should be. For example, the main shaft of the clamp head is generally vulnerable to becoming detached from the main body after a prolonged use of the cutting tool, thereby resulting in a potential safety hazard In addition, the cooling system of the cutting tool is defective in that it is less effective in view of the fact that the coolant is injected on the surface of the work piece intended to be worked on rather than on the working point.
As shown in FIG. 1, a clamp head of cutting tool of prior art comprises a rear sleeve 1A fitted with a push shaft 2A provided at lower end thereof with a plurality of clamp jaws 3A slidable in the rear sleeve 1A. The lower end of the rear sleeve 1A is locked in a front sleeve 1A. The rear sleeve 1A comprises at upper end thereof a locking thread 6A. There are a plurality of steel balls 7A between the locking thread 6 and the rear sleeve 1A. A locking shaft 5A is fitted over by a ferrule 8A. The clamp head is attached to the machine tool by coupling the locking shaft 5A with a main shaft 9. The prior art clamp head described above is defective in design in that its main shaft 9A is vulnerable to becoming detached during rotation and that its cooling system is less effective in view of the fact that it can not execute a cooling exclusively on the working point.